xref: /openbmc/u-boot/lib/string.c (revision 3ba61f06)
1 /*
2  *  linux/lib/string.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  */
6 
7 /*
8  * stupid library routines.. The optimized versions should generally be found
9  * as inline code in <asm-xx/string.h>
10  *
11  * These are buggy as well..
12  *
13  * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
14  * -  Added strsep() which will replace strtok() soon (because strsep() is
15  *    reentrant and should be faster). Use only strsep() in new code, please.
16  */
17 
18 #include <config.h>
19 #include <linux/types.h>
20 #include <linux/string.h>
21 #include <linux/ctype.h>
22 #include <malloc.h>
23 
24 
25 /**
26  * strncasecmp - Case insensitive, length-limited string comparison
27  * @s1: One string
28  * @s2: The other string
29  * @len: the maximum number of characters to compare
30  */
31 int strncasecmp(const char *s1, const char *s2, size_t len)
32 {
33 	/* Yes, Virginia, it had better be unsigned */
34 	unsigned char c1, c2;
35 
36 	c1 = 0;	c2 = 0;
37 	if (len) {
38 		do {
39 			c1 = *s1; c2 = *s2;
40 			s1++; s2++;
41 			if (!c1)
42 				break;
43 			if (!c2)
44 				break;
45 			if (c1 == c2)
46 				continue;
47 			c1 = tolower(c1);
48 			c2 = tolower(c2);
49 			if (c1 != c2)
50 				break;
51 		} while (--len);
52 	}
53 	return (int)c1 - (int)c2;
54 }
55 
56 /**
57  * strcasecmp - Case insensitive string comparison
58  * @s1: One string
59  * @s2: The other string
60  */
61 int strcasecmp(const char *s1, const char *s2)
62 {
63 	return strncasecmp(s1, s2, -1U);
64 }
65 
66 char * ___strtok;
67 
68 #ifndef __HAVE_ARCH_STRCPY
69 /**
70  * strcpy - Copy a %NUL terminated string
71  * @dest: Where to copy the string to
72  * @src: Where to copy the string from
73  */
74 char * strcpy(char * dest,const char *src)
75 {
76 	char *tmp = dest;
77 
78 	while ((*dest++ = *src++) != '\0')
79 		/* nothing */;
80 	return tmp;
81 }
82 #endif
83 
84 #ifndef __HAVE_ARCH_STRNCPY
85 /**
86  * strncpy - Copy a length-limited, %NUL-terminated string
87  * @dest: Where to copy the string to
88  * @src: Where to copy the string from
89  * @count: The maximum number of bytes to copy
90  *
91  * Note that unlike userspace strncpy, this does not %NUL-pad the buffer.
92  * However, the result is not %NUL-terminated if the source exceeds
93  * @count bytes.
94  */
95 char * strncpy(char * dest,const char *src,size_t count)
96 {
97 	char *tmp = dest;
98 
99 	while (count-- && (*dest++ = *src++) != '\0')
100 		/* nothing */;
101 
102 	return tmp;
103 }
104 #endif
105 
106 #ifndef __HAVE_ARCH_STRLCPY
107 /**
108  * strlcpy - Copy a C-string into a sized buffer
109  * @dest: Where to copy the string to
110  * @src: Where to copy the string from
111  * @size: size of destination buffer
112  *
113  * Compatible with *BSD: the result is always a valid
114  * NUL-terminated string that fits in the buffer (unless,
115  * of course, the buffer size is zero). It does not pad
116  * out the result like strncpy() does.
117  */
118 size_t strlcpy(char *dest, const char *src, size_t size)
119 {
120 	size_t ret = strlen(src);
121 
122 	if (size) {
123 		size_t len = (ret >= size) ? size - 1 : ret;
124 		memcpy(dest, src, len);
125 		dest[len] = '\0';
126 	}
127 	return ret;
128 }
129 #endif
130 
131 #ifndef __HAVE_ARCH_STRCAT
132 /**
133  * strcat - Append one %NUL-terminated string to another
134  * @dest: The string to be appended to
135  * @src: The string to append to it
136  */
137 char * strcat(char * dest, const char * src)
138 {
139 	char *tmp = dest;
140 
141 	while (*dest)
142 		dest++;
143 	while ((*dest++ = *src++) != '\0')
144 		;
145 
146 	return tmp;
147 }
148 #endif
149 
150 #ifndef __HAVE_ARCH_STRNCAT
151 /**
152  * strncat - Append a length-limited, %NUL-terminated string to another
153  * @dest: The string to be appended to
154  * @src: The string to append to it
155  * @count: The maximum numbers of bytes to copy
156  *
157  * Note that in contrast to strncpy, strncat ensures the result is
158  * terminated.
159  */
160 char * strncat(char *dest, const char *src, size_t count)
161 {
162 	char *tmp = dest;
163 
164 	if (count) {
165 		while (*dest)
166 			dest++;
167 		while ((*dest++ = *src++)) {
168 			if (--count == 0) {
169 				*dest = '\0';
170 				break;
171 			}
172 		}
173 	}
174 
175 	return tmp;
176 }
177 #endif
178 
179 #ifndef __HAVE_ARCH_STRCMP
180 /**
181  * strcmp - Compare two strings
182  * @cs: One string
183  * @ct: Another string
184  */
185 int strcmp(const char * cs,const char * ct)
186 {
187 	register signed char __res;
188 
189 	while (1) {
190 		if ((__res = *cs - *ct++) != 0 || !*cs++)
191 			break;
192 	}
193 
194 	return __res;
195 }
196 #endif
197 
198 #ifndef __HAVE_ARCH_STRNCMP
199 /**
200  * strncmp - Compare two length-limited strings
201  * @cs: One string
202  * @ct: Another string
203  * @count: The maximum number of bytes to compare
204  */
205 int strncmp(const char * cs,const char * ct,size_t count)
206 {
207 	register signed char __res = 0;
208 
209 	while (count) {
210 		if ((__res = *cs - *ct++) != 0 || !*cs++)
211 			break;
212 		count--;
213 	}
214 
215 	return __res;
216 }
217 #endif
218 
219 #ifndef __HAVE_ARCH_STRCHR
220 /**
221  * strchr - Find the first occurrence of a character in a string
222  * @s: The string to be searched
223  * @c: The character to search for
224  */
225 char * strchr(const char * s, int c)
226 {
227 	for(; *s != (char) c; ++s)
228 		if (*s == '\0')
229 			return NULL;
230 	return (char *) s;
231 }
232 #endif
233 
234 const char *strchrnul(const char *s, int c)
235 {
236 	for (; *s != (char)c; ++s)
237 		if (*s == '\0')
238 			break;
239 	return s;
240 }
241 
242 #ifndef __HAVE_ARCH_STRRCHR
243 /**
244  * strrchr - Find the last occurrence of a character in a string
245  * @s: The string to be searched
246  * @c: The character to search for
247  */
248 char * strrchr(const char * s, int c)
249 {
250        const char *p = s + strlen(s);
251        do {
252 	   if (*p == (char)c)
253 	       return (char *)p;
254        } while (--p >= s);
255        return NULL;
256 }
257 #endif
258 
259 #ifndef __HAVE_ARCH_STRLEN
260 /**
261  * strlen - Find the length of a string
262  * @s: The string to be sized
263  */
264 size_t strlen(const char * s)
265 {
266 	const char *sc;
267 
268 	for (sc = s; *sc != '\0'; ++sc)
269 		/* nothing */;
270 	return sc - s;
271 }
272 #endif
273 
274 #ifndef __HAVE_ARCH_STRNLEN
275 /**
276  * strnlen - Find the length of a length-limited string
277  * @s: The string to be sized
278  * @count: The maximum number of bytes to search
279  */
280 size_t strnlen(const char * s, size_t count)
281 {
282 	const char *sc;
283 
284 	for (sc = s; count-- && *sc != '\0'; ++sc)
285 		/* nothing */;
286 	return sc - s;
287 }
288 #endif
289 
290 #ifndef __HAVE_ARCH_STRCSPN
291 /**
292  * strcspn - Calculate the length of the initial substring of @s which does
293  * not contain letters in @reject
294  * @s: The string to be searched
295  * @reject: The string to avoid
296  */
297 size_t strcspn(const char *s, const char *reject)
298 {
299 	const char *p;
300 	const char *r;
301 	size_t count = 0;
302 
303 	for (p = s; *p != '\0'; ++p) {
304 		for (r = reject; *r != '\0'; ++r) {
305 			if (*p == *r)
306 				return count;
307 		}
308 		++count;
309 	}
310 	return count;
311 }
312 #endif
313 
314 #ifndef __HAVE_ARCH_STRDUP
315 char * strdup(const char *s)
316 {
317 	char *new;
318 
319 	if ((s == NULL)	||
320 	    ((new = malloc (strlen(s) + 1)) == NULL) ) {
321 		return NULL;
322 	}
323 
324 	strcpy (new, s);
325 	return new;
326 }
327 #endif
328 
329 #ifndef __HAVE_ARCH_STRSPN
330 /**
331  * strspn - Calculate the length of the initial substring of @s which only
332  *	contain letters in @accept
333  * @s: The string to be searched
334  * @accept: The string to search for
335  */
336 size_t strspn(const char *s, const char *accept)
337 {
338 	const char *p;
339 	const char *a;
340 	size_t count = 0;
341 
342 	for (p = s; *p != '\0'; ++p) {
343 		for (a = accept; *a != '\0'; ++a) {
344 			if (*p == *a)
345 				break;
346 		}
347 		if (*a == '\0')
348 			return count;
349 		++count;
350 	}
351 
352 	return count;
353 }
354 #endif
355 
356 #ifndef __HAVE_ARCH_STRPBRK
357 /**
358  * strpbrk - Find the first occurrence of a set of characters
359  * @cs: The string to be searched
360  * @ct: The characters to search for
361  */
362 char * strpbrk(const char * cs,const char * ct)
363 {
364 	const char *sc1,*sc2;
365 
366 	for( sc1 = cs; *sc1 != '\0'; ++sc1) {
367 		for( sc2 = ct; *sc2 != '\0'; ++sc2) {
368 			if (*sc1 == *sc2)
369 				return (char *) sc1;
370 		}
371 	}
372 	return NULL;
373 }
374 #endif
375 
376 #ifndef __HAVE_ARCH_STRTOK
377 /**
378  * strtok - Split a string into tokens
379  * @s: The string to be searched
380  * @ct: The characters to search for
381  *
382  * WARNING: strtok is deprecated, use strsep instead.
383  */
384 char * strtok(char * s,const char * ct)
385 {
386 	char *sbegin, *send;
387 
388 	sbegin  = s ? s : ___strtok;
389 	if (!sbegin) {
390 		return NULL;
391 	}
392 	sbegin += strspn(sbegin,ct);
393 	if (*sbegin == '\0') {
394 		___strtok = NULL;
395 		return( NULL );
396 	}
397 	send = strpbrk( sbegin, ct);
398 	if (send && *send != '\0')
399 		*send++ = '\0';
400 	___strtok = send;
401 	return (sbegin);
402 }
403 #endif
404 
405 #ifndef __HAVE_ARCH_STRSEP
406 /**
407  * strsep - Split a string into tokens
408  * @s: The string to be searched
409  * @ct: The characters to search for
410  *
411  * strsep() updates @s to point after the token, ready for the next call.
412  *
413  * It returns empty tokens, too, behaving exactly like the libc function
414  * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
415  * Same semantics, slimmer shape. ;)
416  */
417 char * strsep(char **s, const char *ct)
418 {
419 	char *sbegin = *s, *end;
420 
421 	if (sbegin == NULL)
422 		return NULL;
423 
424 	end = strpbrk(sbegin, ct);
425 	if (end)
426 		*end++ = '\0';
427 	*s = end;
428 
429 	return sbegin;
430 }
431 #endif
432 
433 #ifndef __HAVE_ARCH_STRSWAB
434 /**
435  * strswab - swap adjacent even and odd bytes in %NUL-terminated string
436  * s: address of the string
437  *
438  * returns the address of the swapped string or NULL on error. If
439  * string length is odd, last byte is untouched.
440  */
441 char *strswab(const char *s)
442 {
443 	char *p, *q;
444 
445 	if ((NULL == s) || ('\0' == *s)) {
446 		return (NULL);
447 	}
448 
449 	for (p=(char *)s, q=p+1; (*p != '\0') && (*q != '\0'); p+=2, q+=2) {
450 		char  tmp;
451 
452 		tmp = *p;
453 		*p  = *q;
454 		*q  = tmp;
455 	}
456 
457 	return (char *) s;
458 }
459 #endif
460 
461 #ifndef __HAVE_ARCH_MEMSET
462 /**
463  * memset - Fill a region of memory with the given value
464  * @s: Pointer to the start of the area.
465  * @c: The byte to fill the area with
466  * @count: The size of the area.
467  *
468  * Do not use memset() to access IO space, use memset_io() instead.
469  */
470 void * memset(void * s,int c,size_t count)
471 {
472 	unsigned long *sl = (unsigned long *) s;
473 	char *s8;
474 
475 #if !CONFIG_IS_ENABLED(TINY_MEMSET)
476 	unsigned long cl = 0;
477 	int i;
478 
479 	/* do it one word at a time (32 bits or 64 bits) while possible */
480 	if ( ((ulong)s & (sizeof(*sl) - 1)) == 0) {
481 		for (i = 0; i < sizeof(*sl); i++) {
482 			cl <<= 8;
483 			cl |= c & 0xff;
484 		}
485 		while (count >= sizeof(*sl)) {
486 			*sl++ = cl;
487 			count -= sizeof(*sl);
488 		}
489 	}
490 #endif	/* fill 8 bits at a time */
491 	s8 = (char *)sl;
492 	while (count--)
493 		*s8++ = c;
494 
495 	return s;
496 }
497 #endif
498 
499 #ifndef __HAVE_ARCH_MEMCPY
500 /**
501  * memcpy - Copy one area of memory to another
502  * @dest: Where to copy to
503  * @src: Where to copy from
504  * @count: The size of the area.
505  *
506  * You should not use this function to access IO space, use memcpy_toio()
507  * or memcpy_fromio() instead.
508  */
509 void * memcpy(void *dest, const void *src, size_t count)
510 {
511 	unsigned long *dl = (unsigned long *)dest, *sl = (unsigned long *)src;
512 	char *d8, *s8;
513 
514 	if (src == dest)
515 		return dest;
516 
517 	/* while all data is aligned (common case), copy a word at a time */
518 	if ( (((ulong)dest | (ulong)src) & (sizeof(*dl) - 1)) == 0) {
519 		while (count >= sizeof(*dl)) {
520 			*dl++ = *sl++;
521 			count -= sizeof(*dl);
522 		}
523 	}
524 	/* copy the reset one byte at a time */
525 	d8 = (char *)dl;
526 	s8 = (char *)sl;
527 	while (count--)
528 		*d8++ = *s8++;
529 
530 	return dest;
531 }
532 #endif
533 
534 #ifndef __HAVE_ARCH_MEMMOVE
535 /**
536  * memmove - Copy one area of memory to another
537  * @dest: Where to copy to
538  * @src: Where to copy from
539  * @count: The size of the area.
540  *
541  * Unlike memcpy(), memmove() copes with overlapping areas.
542  */
543 void * memmove(void * dest,const void *src,size_t count)
544 {
545 	char *tmp, *s;
546 
547 	if (dest <= src) {
548 		memcpy(dest, src, count);
549 	} else {
550 		tmp = (char *) dest + count;
551 		s = (char *) src + count;
552 		while (count--)
553 			*--tmp = *--s;
554 		}
555 
556 	return dest;
557 }
558 #endif
559 
560 #ifndef __HAVE_ARCH_MEMCMP
561 /**
562  * memcmp - Compare two areas of memory
563  * @cs: One area of memory
564  * @ct: Another area of memory
565  * @count: The size of the area.
566  */
567 int memcmp(const void * cs,const void * ct,size_t count)
568 {
569 	const unsigned char *su1, *su2;
570 	int res = 0;
571 
572 	for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
573 		if ((res = *su1 - *su2) != 0)
574 			break;
575 	return res;
576 }
577 #endif
578 
579 #ifndef __HAVE_ARCH_MEMSCAN
580 /**
581  * memscan - Find a character in an area of memory.
582  * @addr: The memory area
583  * @c: The byte to search for
584  * @size: The size of the area.
585  *
586  * returns the address of the first occurrence of @c, or 1 byte past
587  * the area if @c is not found
588  */
589 void * memscan(void * addr, int c, size_t size)
590 {
591 	unsigned char * p = (unsigned char *) addr;
592 
593 	while (size) {
594 		if (*p == c)
595 			return (void *) p;
596 		p++;
597 		size--;
598 	}
599 	return (void *) p;
600 }
601 #endif
602 
603 #ifndef __HAVE_ARCH_STRSTR
604 /**
605  * strstr - Find the first substring in a %NUL terminated string
606  * @s1: The string to be searched
607  * @s2: The string to search for
608  */
609 char * strstr(const char * s1,const char * s2)
610 {
611 	int l1, l2;
612 
613 	l2 = strlen(s2);
614 	if (!l2)
615 		return (char *) s1;
616 	l1 = strlen(s1);
617 	while (l1 >= l2) {
618 		l1--;
619 		if (!memcmp(s1,s2,l2))
620 			return (char *) s1;
621 		s1++;
622 	}
623 	return NULL;
624 }
625 #endif
626 
627 #ifndef __HAVE_ARCH_MEMCHR
628 /**
629  * memchr - Find a character in an area of memory.
630  * @s: The memory area
631  * @c: The byte to search for
632  * @n: The size of the area.
633  *
634  * returns the address of the first occurrence of @c, or %NULL
635  * if @c is not found
636  */
637 void *memchr(const void *s, int c, size_t n)
638 {
639 	const unsigned char *p = s;
640 	while (n-- != 0) {
641 		if ((unsigned char)c == *p++) {
642 			return (void *)(p-1);
643 		}
644 	}
645 	return NULL;
646 }
647 
648 #endif
649 #ifndef __HAVE_ARCH_MEMCHR_INV
650 static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes)
651 {
652 	while (bytes) {
653 		if (*start != value)
654 			return (void *)start;
655 		start++;
656 		bytes--;
657 	}
658 	return NULL;
659 }
660 /**
661  * memchr_inv - Find an unmatching character in an area of memory.
662  * @start: The memory area
663  * @c: Find a character other than c
664  * @bytes: The size of the area.
665  *
666  * returns the address of the first character other than @c, or %NULL
667  * if the whole buffer contains just @c.
668  */
669 void *memchr_inv(const void *start, int c, size_t bytes)
670 {
671 	u8 value = c;
672 	u64 value64;
673 	unsigned int words, prefix;
674 
675 	if (bytes <= 16)
676 		return check_bytes8(start, value, bytes);
677 
678 	value64 = value;
679 	value64 |= value64 << 8;
680 	value64 |= value64 << 16;
681 	value64 |= value64 << 32;
682 
683 	prefix = (unsigned long)start % 8;
684 	if (prefix) {
685 		u8 *r;
686 
687 		prefix = 8 - prefix;
688 		r = check_bytes8(start, value, prefix);
689 		if (r)
690 			return r;
691 		start += prefix;
692 		bytes -= prefix;
693 	}
694 
695 	words = bytes / 8;
696 
697 	while (words) {
698 		if (*(u64 *)start != value64)
699 			return check_bytes8(start, value, 8);
700 		start += 8;
701 		words--;
702 	}
703 
704 	return check_bytes8(start, value, bytes % 8);
705 }
706 #endif
707